The primary objective of this effort is to develop a program which will have the ultimate capability of testing 1000 chemicals per year using microbial systems, and as-yet-undetermined smaller numbers of chemicals in higher in vitro and in vivo test systems. With this level of testing, it will be necessary to develop the ability for chemical management and analyses of compounds tested. A computerized system for data handling and statistical analysis will also be developed. Substances which are mutagenic in the microbial tests will be tested further using higher systems which serve to affirm or refute the microbial data and more precisely define the types of mutagenic events induced.